Control valves for hydraulic transmission systems for winches



April 25, 1961 H. HILDRE 2,931,239

CONTROL VALVES FOR HYDRAULIC TRANSMISSION SYSTEMS FOR WINCHES FiledMarch 20, 1959 2 Sheets-Sheet 1 INVENTOR: HANS H/LDRE.

April 25, 1961 H. HILDR CONTROL VALVES FOR HYDRAUL SYSTEMS FOR WIN FiledMarch 20, 1959 ia lllq IC TRANSMISSION 2 Sheets-Sheet 2 INVENTOR:

HANS H/LDRE.

United States Patent O F CONTROL VALVES FOR HYDRAULIC TRANS- MISSIONSYSTEMS FOR WINCHES Hans Hildre, Brattvaag, Norway, assignor toHydraulik A/S, Brattvaag, Norway Filed Mar. 20, 1959, Ser. No. 800,817 3Claims. (Cl. 12146.4)

This invention relates to a control valve for hydraulic transmissionsystems and particularly to a control valve for hydraulicwinches for usein the handling of cargo and baggage on board ships and for general useon board fishing boats, such as for hauling in fishing nets and thelike.

Hydraulic transmission systems for which the control valve according tothe present invention is primarily included are described in Patents2,655,000; 2,718,759; 2,618,291; 2,749,709; 2,822,668; and 2,736,170.

' In winches of the kind referred to it is desirable to have means forreturning the control valve to its stop or neutral positionautomatically when the operator disengages his manual control handle. Inthis stop position, the winch drum is stopped and preferably positivelylocked against movement in at least the lowering direction.

It is an object of the present invention to provide a simple, reliableand advantageous return mechanism. of the control handle and itsassociated valve member in such winches.

Another object of the present invention is to provide an arrangementwherein the return movement of the control handle proceeds smoothly andslowly in order to avoid shocks in the hoisting line due to suddenchanges in the hydraulic system.

. Accordingly, the invention consists of a manually perated controlvalve for hydraulic transmission systems, 7

comprising a housing havingv a valve chamber, a supply conduit forpressure fluid from a fluid source to said valve chamber, a conduit fordischarge fluid to said fluid source from said valve chamber, conduitsfor supplying and discharging hydraulic fluid to and from an hydraulicmotor means from and to said valve chamber, all of said conduits openinginto said valve chamber at spaced positions, a slide member displaceablymounted within said valve chamber, said slide member carrying flanges orlands for dividing the valve chamber into communication spaces forsetting up desired flow paths for the hydraulic fluid from one conduitto another within said valve chamber, a man ually operable controlhandle, said control handle being connected to said slide member wherebymovement of said control handle to and from a central position intoeither of two opposite directions will move the slide member so as toshift the flow paths of said valve chamber,

said central position representing a stop position whereas the movementinto a respective one of said opposite directions will set up flow pathsto drive the hydraulic motor means in a respective one of oppositedirections, means for resiliently urging said control handle towards itscentral position, and means for dampening the return movement to saidcentral position resulting from a manual displacement therefrom andsubsequent release of said control handle.

Further objects, advantages and features of the invention will beapparent from the following diescription of one embodiment given by wayof example, with reference to the accompanying drawings, in which: iFigure l is an axial sectional view of an embodiment of a control valveaccording to the present invention, the

valve member being shown in its intermediate or stop position.

Figure 2 is a wide view corresponding to the sectional view of Figure 1,showing. the valve member in its hoisting position, or in the positionof rotating the hydraulic motor in one direction.

Figure 3 is a view corresponding to the sectional views of Figures 1 and2, showing the valve member in its'position of positive lowering, or theposition for rotating the hydraulic motor in the opposite direction.

Figure 4 is a simplified plan view of the valve housing.

Referring now to these drawings the control valve comprises a housing 10enclosing a member 11 axially slidable within a cylindrical valvechamber 12 of said housing. The valve member is at its upper endprovided with a lug 13 to which one end of a link 14 is pivoted, theother end of said link being pivoted to the outer end of a lever 15 theopposite end of which is keyed to a rotatable shaft 16 extending throughpackings (not shown) to the outside of said housing where an operatinghandle 17 iskeyed to said shaft, whereby the axial position of the slidemember within the valve chamber can be shifted by operation of saidhandle.

Pressure fluid is supplied to the housing from a pump, (not shown),through an auxiliary housing 18, from which channels extend to twoopenings 19 and 20 in the Wall of valve chamber 12 at the centralportion thereof with re-' spect to the main axis of the valve chamber. Acheck valve 21 is arranged in said auxiliary housing, the func tion ofwhich is described in the above mentionedPatent No. 2,736,170. In theaxial direction of the valve chamber 12, the openings 19 and 20 areseparated by a wall portion 22.

Discharge fluid is returned from the lower end of the valve chamber 12through an opening 23 leading either to a sump or directly into thesuction pipe of the pump. The upper end of the valve chamber isconstantly connected to the discharge by an opening 24 communicatingthrough a chnnel (not shown) in the wall of the housing with the lowerend of the valve chamber.

At an axial position between the central openings 19, 20 and the upperend opening 24 a motor supply opening 25 is arranged. At an axialposition between the said central openings 19, 20 and the lower endopening 23, a motor discharge opening is arranged.

The slide member 11 carries at its upper end two disc shaped platemembers together forming'an upper flange or land 27, at its centralportion a number of disc shaped plates together forming a broad centralflange or land 28, and a lower flange or land 29 at its lower end.

To the upper end cover 30 of the housing a downwardly extending rod 31is secured, said rod carrying at its lower end a piston 32 arrangedwithin an interior cylinder bore 33 of the slide member. Said cylinderbore 33 of the slide member is open at its lower end, whereas its upperend is closed by a plate member 34 forming an integral part of the upperflange. A first tubular sleeve 35 surrounds the rod 31 and extendsupwards, the upper end of said sleeve 35 being spaced from the lowerface of top cover 30 in the position of Figure 1. Furthermore, saidsleevev is surrounded by a first compression spring 36 between the topcover 30 and the plate member 34.

A second compression spring 37 is arranged between the lower face of theplate member 34 and a spring supporting disc 38. A second tubular sleeve39 is secured to or rests on said spring supporting member, said sleevesurrounding the rod and extending upwardly to terminate at apredetermined distance from the lower face of the plate member 34. Inthe stop or neutral position of the slide member, the spring supportingdisc 38 rests on two Patented Apr. 25, 1961 stops 40 preventingdownwards movement of the disc 38, in said neutral or stop position thespring supporting disc further rests on a third tubular sleeve 41surrounding the rod 31. and extending upwards from the piston 32 to. thelower face of the spring supporting disc 38. I

It should be noted that the three sleeves 35, 39 and41 preferably onlyloosely surround the rod 31 so asto rest under their own weight on theirrespective supporting part, there beingno necessity for saidsleeves tobe secured to such supporting parts.

Adjacent to the. lower face of the broad intermediate flangeor land 28,a narrow radial passage 42 extends from the peripheryof said flange tothe hollow interior of the slide member. Said passage is situated sothat in thestop. or neutral position its opening will be covered by thewall portion 22 between the central supply openings 19 and 20.

The upper plate member 34 is provided with another narrow passage 43extending from the outside of the slide member into the hollow interiorthereof.

It should also be noted that a locking member 44 having a fork-shapedconstruction as shown in Figure 4 is pivotally mounted for rotationabout a horizontal pivot 45. By swinging said for]; member downwards,the operating handle may be locked in the stop or neutral position toprevent it from being displaced inadvertently from said position.Furthermore, a sheave member 46 is arranged to guide the handle as wellas to assist the operator by being provided with markings showing thehoisting, lowering and stop positions, and also the intermediatepositions of hoisting at reduced speeds.

Mode of operation is connected to the suction line 23 and the opening 26to the inlet 20.

In the posit-ion of Figure 2, representing full hoisting position, theslidemember will be positioned at its lowermost position. In addition tothe prior used arrangement of this control valve, such downwardsmovement of the slide member is limited by the upper end plate 34engaging in this position with its lower face the upper end of thesleeve 39, said sleeve resting on the spring supporting disc 41, whereassaid spring supporting disc 38 rests on the lower sleeve 41, which inturn rests. on or is associated with-the piston 32, whereby the downwardmovement of the slide member is limited to this extreme posit-ion.

In said. extreme position the lower spring 37, which is received betweenthe end plate 34 and the spring support 38, will be compressed; as isobvious the said-spring will create a return torceas soon as theoperator releases the handle.

In may be. advantageous, at the present stage of des scription, toconsider the corresponding arrangement in the position of Figure 3,representing the position of full lowering, said. posit-ion being. theuppermost position possible of the slide member in the valve chamber.

Said upper end position is limited by the upper sleeve 35 engaging thelower face of the top cover 30 of-the housing; simultaneously, the upperspring 36 will be compressed between said top cover and the plate 34.This will give. a downwards directed return force.

However, the slide member has a substantial weight, which. in additionto the spring force willact to, force theslide member downwards. Inorder tocounterbalance such weight of the slide member, the lower spring37 is 4 given a pre-compression corresponding to said weight. Inaddition, both springs are given a small counteracting pre-compressionin order to ensure correct return to the neutral position. It will bereadily understood that the arrangement will give the desired returnmovement of the slide member, as soon as the operator releases thehandle 17.

Although the entire valve chamber is filled with hydraulic fluid such asoil, the return movements aforesaid may nevertheless proceed at adangerously high rate due to the high volume of fluid passing throughthe valve per unit of time in such valves for hydraulic winches of thestated kind. Furthermore, it is desirable to have relatively high returnspring force in order to ensure safe return to the neutral position,which will necessarily give a high rate of return movement. This isdangerous, because the system will be subjected to abrupt changes inflow directions.

First of all, it shouldbe obvious that movement towards the position ofhoisting will decrease the volume of the space within the slide member;said volume must in other words be increased again at the returnmovement to stop position. When moving the slide member towards theposition of lowering, the said volume is increased and must be decreasedwhen returning towards the stop position. During the first mentionedmovement, hydraulic fluid must be sucked through the narrow passages 42and 43, while during the second type of movement, the fluid must bepressed therethrough; consequently, an hydraulic dampening means will beenclosed in thehollow interior of the valve, such dampening meansconsisting in passing of hydraulic fluid to and from the interior spacethrough narrow passages 42 and 43. For this reason, the return movementwill proceed at a safely low rate.

However, when moving the valve member downwards, pressure fluid from thelower opening 20 will also flow from the supply conduit through thepassage 42 ofthe intermediate flange 28, and will pass through thehollow interior of the slide member and through the passage 43 of theupper plate member 34; this flow will result in a slight increase of thepressure towards the slide member at its upper end when same is moved ina downward direction. As is well known in the art, such slide valves arenormally counterbalanced as to pressure by having end flanges of equaldiameters, both end flanges being subjected to the same pressure, thatis, discharge pressure in the present embodiment. However, thiscounterbalance'will be somewhat changed during the downward movement,due to the flow aforesaid.

The unbalance, although small, supports the downward movement of theslide member, making it easy to move same downwards. A remarkablefeature is that the stated effect is more significant at higherpressures, that is, when higher loads are hoisted. At such higherpressures there will normally be a higher need for such assistance inthe downward movementyas the high pressure-of the fluid flowing from thesupply openings 19 and 2! will tend to urge the slide member laterallytowards the wall of the valve chamber, whereby the friction between theslide member and the wall is increased.

In the upward movement of the slide'mem ber towards the loweringposition, such higher pressures will not be created in the system.Furthermore, when lowering higher loads, there will be a'flow underhighpressure from the bpeningZ-S to the opening 24, which will create anupwards directed force .to assist the movement towards the upper, endposition.

The flow conditions mentioned above, will not materially affect thereturn movements explained previously.

While there is in this application specifically illustrated anddescribed one form which the invention may assume in practice, itwillofcourse be understood that the showing provided is for the purpose ofillustration onlyand that the invention may be further modified andembodied in various other forms without departing from its scope asdefined by the appended claims.

What I claim is:

1. A manually operated control valve for hydraulic transmission systems,comprising a housing having a valve chamber, a supply conduit coupled tosaid housing and adapted for conveying pressure fluid from a fluidsource to said valve chamber, a conduit coupled to said housing andadapted for conveying discharge fluid back to said fluid source fromsaid valve chamber, conduits coupled to said housing and adapted forsupplying and discharging hydraulic fluid to and from a hydraulic motormeans from and to said valve chamber, all of said conduits opening intosaid valve chamber at spaced positions, a slide member displaceablymounted within said valve chamber, said slide member including flangesfor dividing the valve chamber into communication spaces for setting updesired flow paths for the hydraulic fluid from one conduit to anotherwithin said valve chamber, a manually operable control handle, saidcontrol handle being connected to the slide member whereby movement ofsaid control handle to and from a central position into one of twoopposite directions will move the slide membe: so as to shift the flowpaths of said valve chamber, said central position representing a stopposition of said motor means whereas the movement into a respective oneof said opposite directions is adapted to set up flow paths to drive thehydraulic motor means in a respective one of opposite directions, meansfor resiliently urging said control handle towards its central position,and means for dampening the return movement to said central position asa result of a manual displacement therefrom and subsequent release ofsaid control handle, said valve further comprising two compressionsprings arranged to urge the slide member towards a stop position incounteracting arrangement, one of said compression springs beingarranged to receive and counteract the weight of the slide member.

2. A manually operated control valve for hydraulic systems. comprising ahousing having a cylindrical valve chamber bore, a piston connected tosaid housing, conduits adapted for connection to and from a pressurefluid source leading into said bore at axially spaced positions therein.conduits adapted for connection to and from a hydraulic motor means andleading into said bore at other axially spaced positions therein, aslide member axially displaceable within said bore, said slide membercarrying flanges for dividing said bore axially into a number of closedspaces for setting up communication paths between sard conduits,manually operated means for axially displacing said slide member withinsaid bore to shift the pattern of communication paths between saidconduits, return means for said slide member, a cylindrical space withinsaid slide member, said cylindrical space being closed at one end andreceiving at its opposite end the piston connected to said housing, anda restricted passage for supplying hydraulic fluid to the space withinthe slide member, the axis of said bore extending substantially in avertical direction, the return means for said slide member comprisingcompression springs arranged in counteracting arrangement to urge thevalve member to a central position, one of the compression springsurging the valve member in an upward direction and having a forcesuflicient to counteract the weight of the slide member as well as theforce from the other spring which acts downwardly.

3. A manually operated control valve according to claim 2, wherein arestricted flow of fluid is set up to assist in the manually operatedmovement of the control valve member in movements from the centralposition.

References Cited in the file of this patent UNITED STATES PATENTS2,062.126

